eliminate global and file-scope static variables in oct-hist.cc * interpreter.h, interpreter.cc (interpreter::m_history_system, interpreter::get_history_system): New member variable and access function. * interpreter-private.h, interpreter-private.cc (__get_history_system__): New function. * oct-hist.h, oct-hist.cc: Rewrite to use class for command history configuration variables and functions. Change all uses.

--- a/libinterp/parse-tree/lex.h	Wed Oct 31 18:22:23 2018 -0400
+++ b/libinterp/parse-tree/lex.h	Wed Oct 31 19:32:41 2018 -0400
@@ -711,6 +711,8 @@
 
     virtual bool input_from_eval_string (void) const { return false; }
 
+    bool input_from_tmp_history_file (void);
+
     void push_start_state (int state);
 
     void pop_start_state (void);